Development of an Adherence to Anticoagulant Therapy Scale: A Validity and Reliability Study

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Kankaya E. A., Bilik Ö.

JOURNAL OF BASIC AND CLINICAL HEALTH SCIENCES, cilt.6, sa.6, ss.815-823, 2022 (ESCI) identifier identifier

Özet

Purpose: Anticoagulants are an important group of drugs used by many patients with different diseases.There are general adherence scales that measure adherence to treatment in the literature. However, thecorrect use of the drug alone is not sufficient for adherence with warfarin therapy. We aimed to developAnticoagulant Therapy Adherence Scale for use in patients on warfarin and to examine psycholinguisticand psychometric properties.Material and Methods: The research was of a methodological and consisted of 170 patients. The validityof the scale was tested by using content validity, explanatory and confirmatory factor analysis. Thereliability of the scale was examined by utilizing item-total scale correlations and Cronbach’s alpha.Results: After the scale items were created, opinions were received from twenty experts and contentvalidity indexes were found to be above 0.80. In the explanatory factor analysis, a 3-factor structure withfactor loads between 0.30 and 0.81 was obtained. Fit indices obtained in the confirmatory factor analysiswere as follows: χ2 = 181.116, df = 116 χ2/df value 1.561, Root Mean Square Error of Approximation(RMSEA) = 0.058, Comparative Fit Index (CFI): 0.88 and Goodness Fit Index (GFI): 0.88. Item-total scalecorrelation coefficients were found to range between 0.57 and 0.25. The Cronbach's alpha reliabilitycoefficient was 0.74 for the overall scale and 0.63, 0.77 and 0.65 for its subscales.Conclusion: ATAS was found to be a valid and reliable measurement tool in Turkish population. Thescale can be used by healthcare professionals to evaluate patients' use of warfarin in a standard Purpose: Anticoagulants are an important group of drugs used by many patients with different diseases.There are general adherence scales that measure adherence to treatment in the literature. However, thecorrect use of the drug alone is not sufficient for adherence with warfarin therapy. We aimed to developAnticoagulant Therapy Adherence Scale for use in patients on warfarin and to examine psycholinguisticand psychometric properties.Material and Methods: The research was of a methodological and consisted of 170 patients. The validityof the scale was tested by using content validity, explanatory and confirmatory factor analysis. Thereliability of the scale was examined by utilizing item-total scale correlations and Cronbach’s alpha.Results: After the scale items were created, opinions were received from twenty experts and contentvalidity indexes were found to be above 0.80. In the explanatory factor analysis, a 3-factor structure withfactor loads between 0.30 and 0.81 was obtained. Fit indices obtained in the confirmatory factor analysiswere as follows: χ2 = 181.116, df = 116 χ2/df value 1.561, Root Mean Square Error of Approximation(RMSEA) = 0.058, Comparative Fit Index (CFI): 0.88 and Goodness Fit Index (GFI): 0.88. Item-total scalecorrelation coefficients were found to range between 0.57 and 0.25. The Cronbach's alpha reliabilitycoefficient was 0.74 for the overall scale and 0.63, 0.77 and 0.65 for its subscales.Conclusion: ATAS was found to be a valid and reliable measurement tool in Turkish population. Thescale can be used by healthcare professionals to evaluate patients' use of warfarin in a standard Purpose: Anticoagulants are an important group of drugs used by many patients with different diseases.There are general adherence scales that measure adherence to treatment in the literature. However, thecorrect use of the drug alone is not sufficient for adherence with warfarin therapy. We aimed to developAnticoagulant Therapy Adherence Scale for use in patients on warfarin and to examine psycholinguisticand psychometric properties.Material and Methods: The research was of a methodological and consisted of 170 patients. The validityof the scale was tested by using content validity, explanatory and confirmatory factor analysis. Thereliability of the scale was examined by utilizing item-total scale correlations and Cronbach’s alpha.Results: After the scale items were created, opinions were received from twenty experts and contentvalidity indexes were found to be above 0.80. In the explanatory factor analysis, a 3-factor structure withfactor loads between 0.30 and 0.81 was obtained. Fit indices obtained in the confirmatory factor analysiswere as follows: χ2 = 181.116, df = 116 χ2/df value 1.561, Root Mean Square Error of Approximation(RMSEA) = 0.058, Comparative Fit Index (CFI): 0.88 and Goodness Fit Index (GFI): 0.88. Item-total scalecorrelation coefficients were found to range between 0.57 and 0.25. The Cronbach's alpha reliabilitycoefficient was 0.74 for the overall scale and 0.63, 0.77 and 0.65 for its subscales.Conclusion: ATAS was found to be a valid and reliable measurement tool in Turkish population. Thescale can be used by healthcare professionals to evaluate patients' use of warfarin in a standard way.

Purpose: Anticoagulants are an important group of drugs used by many patients with different diseases.There are general adherence scales that measure adherence to treatment in the literature. However, thecorrect use of the drug alone is not sufficient for adherence with warfarin therapy. We aimed to developAnticoagulant Therapy Adherence Scale for use in patients on warfarin and to examine psycholinguisticand psychometric properties.Material and Methods: The research was of a methodological and consisted of 170 patients. The validityof the scale was tested by using content validity, explanatory and confirmatory factor analysis. Thereliability of the scale was examined by utilizing item-total scale correlations and Cronbach’s alpha.Results: After the scale items were created, opinions were received from twenty experts and contentvalidity indexes were found to be above 0.80. In the explanatory factor analysis, a 3-factor structure withfactor loads between 0.30 and 0.81 was obtained. Fit indices obtained in the confirmatory factor analysiswere as follows: χ2 = 181.116, df = 116 χ2/df value 1.561, Root Mean Square Error of Approximation(RMSEA) = 0.058, Comparative Fit Index (CFI): 0.88 and Goodness Fit Index (GFI): 0.88. Item-total scalecorrelation coefficients were found to range between 0.57 and 0.25. The Cronbach's alpha reliabilitycoefficient was 0.74 for the overall scale and 0.63, 0.77 and 0.65 for its subscales.Conclusion: ATAS was found to be a valid and reliable measurement tool in Turkish population. Thescale can be used by healthcare professionals to evaluate patients' use of warfarin in a standard way.